There is a growing concern about carbon source after the depletion of fossil fuels in the world of polymeric materials, as the majority of the commercialized polymer products are related to petrochemical resources, such as polystyrene, polyvinyl chloride, polypropylene, and polyethylene terephthalate. Renewable resources, such as carbohydrate, lignin, cellulose and plant oils, gain attention for the production of polymeric materials, due to their short term of reproducibility from biomass. Plant oils, mainly constituting of triglycerides, are extracted primarily from the seeds of oilseed plants. Besides the basic consumption as food, other applications are developed from this bio-renewable resource, like lubricants, biofuels, plasticizers, and construction materials. These triglycerides are also candidates as the building block of polymeric materials considering their natural abundance and inherent functionality, like the unsaturated double bond and ester groups. Challenges still present, including their heterogeneous and non-uniform structures. Plant oils have been used directly as the monomers for the preparation of cross-linked materials through the polymerization of their unsaturated alkyl chains for the applications in painting and floor coverings. Modifications of triglycerides through the unsaturated fatty acids have been attempted in the method of isomerization, epoxidation, reduction, hydroformylation, and metathesis reactions. Transformations of the triglycerides at the ester bonds have been focused on hydrolysis and transesterification to separate fatty acids from the glycerol core. Besides major applications in biodiesel manufacturing, triglyceride-derived fatty acids can be made into polymeric materials that are attractive for medical applications as they are naturally occurring and biocompatible. However, the preparation of processable polymers has not been well developed. The major challenge is the lack of both synthetic strategies to convert plant oil to polymerizable monomers, and polymerization techniques that do not affect the un-saturated double bonds in the fatty acids. This situation also limits the possibility of substituting petroleum based polymers with bio-renewable polymers in the areas of thermoplastic elastomers, thermoplastic resins, polymeric wax, varnishes, coatings, etc.